Chadduck W M, Seibert J J, Adametz J, Glasier C M, Crabtree M, Stansell C A
Department of Neurosurgery, Arkansas Children's Hosptial, University of Arkansas for Medical Sciences, Little Rock, 72202.
Surg Neurol. 1989 Feb;31(2):122-8. doi: 10.1016/0090-3019(89)90324-8.
Using pulsed Doppler ultrasound through the sonic window of the anterior fontanelle in infants, 46 children with ventriculomegaly had sequential evaluations of Resistive Index for comparison with the need for ventriculoperitoneal shunting. Hydrocephalus was associated with myelomeningocele in 17 patients and posthemorrhagic, postmeningitic, or congenital hydrocephalus accounted for the rest. The Resistive Index was obtained by dividing the difference between the peak systolic and end diastolic frequencies by the systolic frequency. Criteria for shunting included massive ventriculomegaly, increasing ventriculomegaly with an abnormal increase in head circumference, and clinical evidence of symptomatic hydrocephalus. Those patients requiring shunts had a Resistive Index of 84 +/- 13% prior to shunting. The Resistive Index fell to 72 +/- 11% postshunting with the difference being statistically significant at p less than 0.001. Moreover, the postshunting values compared favorably to data on 29 normal newborns, having Resistive Indices of 71 +/- 7% and to the Resistive Indices of three patients never shunted who had values of 74%, 66%, and 71%. Variations included primarily low Resistive Indices in myelomeningocele patients whose ventricles were decompressed by the leaking spinal lesions. Resistive Index used in conjunction with clinical observations may be extremely helpful not only in predicting the need for ventriculoperitoneal shunt, but also in evaluating children suspected of shunt malfunctions.